* {
  padding: 0;
  margin: 0;
  text-decoration: none;
  list-style: none;
}

.box {
  width: 100%;
  height: 100%;
}

.box header {
  width: 100%;
  height: 69px;
  line-height: 69px;
  background: var(--bgcolor);
  border-bottom: 1px solid #000;
}

.box header .box {
  display: flex;
  width: 1200px;
  height: 100%;
  margin: 0 auto;
  align-items: center;
}

.box header .box img {
  width: 36px;
  height: 36px;
}

.box header .box .nav {
  display: flex;
  width: 50%;
  margin-left: 5%;
}

.box header .box .nav li {
  flex: 1;
  margin: 0;
}

.box header .box .nav a {
  color: var(--color);
}

.box header .box .nav a:hover {
  color: red;
}

.box header .box .navrigth {
  display: flex;
  width: 30%;
  height: 100%;
  justify-content: space-evenly;
  align-items: center;
}

.box main {
  display: flex;
  width: 100%;
  justify-content: center;
  align-items: center;
  background-color: var(--mainbg);
}

footer {
  width: 100%;
  height: 100px;
  border-top: 2px solid #ccc;
  background-color: #282c35;
}

.search {
  width: 75%;
  margin: 0 auto;
}

.search .sernav {
  display: flex;
  width: 100%;
  font-size: 32px;
  line-height: 80px;
  justify-content: space-between;
}

.search .sernav span {
  color: #ccc;
}

.search .serinp {
  display: flex;
  width: 100%;
}

.search .serinp input {
  width: 95%;
  height: 32px;
  border-color: #ccc;
}

.search .serinp input:hover {
  border-color: #f70c0c;
}

.search .serinp svg {
  flex: 1;
  height: 32px;
  margin-left: -1px;
  border-top: 2px solid #ccc;
  border-right: 2px solid #ccc;
  border-bottom: 2px solid #ccc;
}

.centerbox {
  width: 100%;
  height: 100%;
}

.centerbox .centercon {
  display: flex;
  width: 1000px;
  height: 100%;
  padding: 20px 0;
  margin: 0 auto;
  justify-content: space-around;
}

.centerbox .centercon .centerleft {
  width: 600px;
  height: 850px;
  padding: 10px;
  background: #fff;
}

.centerbox .centercon .centerleft span {
  color: red;
}

.centerbox .centercon .centerleft li {
  font-weight: bold;
  line-height: 40px;
}

.centerbox .centercon .centerright {
  width: 300px;
  height: 850px;
  padding: 10px;
}

.centerbox .centercon .centerright .topbox {
  width: 300px;
  height: 250px;
  margin-bottom: 50px;
  background: #fff;
}

.centerbox .centercon .centerright .topbox li {
  font-size: 13px;
  line-height: 30px;
}

.centerbox .centercon .centerright .topbox h4 {
  line-height: 35px;
  border-bottom: 1px solid #ccc;
}

.centerbox .centercon .centerright .botbox {
  width: 300px;
  height: 400px;
  background: #fff;
}

.centerbox .centercon .centerright .botbox li {
  font-size: 13px;
  line-height: 35px;
}

.centerbox .centercon .centerright .botbox h4 {
  line-height: 35px;
  border-bottom: 1px solid #ccc;
}

.knowledgebooks {
  display: flex;
  width: 1200px;
  height: 100%;
  margin: 0 auto;
}

.knowledgebooks .knowleft {
  float: left;
  width: 700px;
  height: 100%;
  margin-top: 20px;
}

.knowledgebooks .knowleft .cen {
  width: 100%;
  text-align: center;
}

.knowledgebooks .knowleft .knowheaderbox {
  width: 100%;
  height: 200px;
}

.knowledgebooks .knowleft .knowheaderbox .knowheaderbox2 {
  width: 95%;
  height: 90%;
  margin-left: 15px;
}

.knowledgebooks .knowleft .knowheaderboxheader {
  width: 100%;
  height: 30px;
  line-height: 30px;
}

.knowledgebooks .knowleft .knowheaderboxmain {
  width: 100%;
  height: 150px;
  margin-top: 10px;
}

.knowledgebooks .knowleft .knowheaderboxmain img {
  width: 240px;
  height: 130px;
  margin-top: 10px;
}

.knowledgebooks .knowheaderboxmainright {
  float: right;
  width: 410px;
  height: 130px;
  margin-top: 10px;
  font-size: 15px;
}

.knowledgebooks .knowright {
  float: right;
  width: 400px;
  height: 100%;
  padding-top: 20px;
  margin-left: 100px;
}

.knowledgebooks .knowright .knowrighttopmain {
  padding-top: 20px;
  font-size: 16px;
  line-height: 10px;
}

.knowrightbottom1 {
  margin-top: 50px;
}

.knowrightbottom {
  margin-top: 50px;
  line-height: 30px;
}
